The Triassic palaeogeographic transition between the Alpujarride and Malaguide complexes. Betic–Rif Internal Zone (S Spain, N Morocco)

Abstract

Various tectonic units situated between the Malaguide and Alpujarride complexes (in the Betic–Rif Internal Zone, S Spain and N Morocco) present Triassic successions sharing features of both complexes the presence of which indicates a transitional domain. These units (which we term Intermediate units) are situated preferentially near the external limit of the Betic–Rif Internal Zone, generally adapted to the shape of the Arc of Gibraltar. The palaeogeography of this area is reconstructed on the basis of the general geometric position of these units and their relationships with equivalent domains in the western Mediterranean, the scarce existing palaeomagnetic data and the directions of tectonic displacement. The most problematic reconstructions concern those units on the N border of the Betic–Rif Zone, as they have significant clockwise rotations (up to 200°), S and SE tectonic displacements, and a different geometric distribution from the rest of the units. We conclude that in general the transition between the Malaguide and Alpujarride complexes was gradual, the Malaguide domain located S of the Alpujarride, with the intermediate units lying, evidently, between the two complexes.